KOOI-REACHFORKS ® extend hydraulically. They can be used on virtually any type of lift truck and can solve a variety of materials handling challenges. Some of the most common uses include loading and unloading trailers or rail cars from one side, double-deep storage with conventional lift trucks and dual load handling without loose fork extensions. KS ® extend hydraulically. They can be used on virtually any type of lift truck and can solve a variety of materials handling challenges. Some of the most common uses include loading and unloading trailers or rail cars from one side, double-deep storage with conventional lift trucks and dual load handling without loose fork extensions.